Die



Aug. 5, 1947. L H. M. YBOLSTQN 2,425,082

' DIE Filed March 25, 1946 Patented Aug. 5, 1947 DIE Harry M. Bolston, Swampscott, Mass.

Application March 23, 1946, Serial No. 656,699

3 Claims. 1

This invention relates to dies for cutting out shoe Vamps, and other blanks from'sheet material, such as leather, plastic, rubber, fabric and the like.

Dies of this nature generally comprise a continuous, fiat, metal strip shaped to correspond to the outline or contour of the shoe vamp or other piece desired to be cut out. The die is arranged to lie fiat on the sheet material to be cut, with the sides upright or in a vertical plane, and its edges thus lying in spaced parallel planes, one or both of which edges are sharpened to provide a continuous cutting edge. Such dies are generally used in a clicker machine, having a fiat platform or cutting block, of wood, rubber, or fiber, on which is placed the sheet material from which the blanks are to be cut out, with the die placed on top of or between sheets of the blank material. The machine is provided with an arm which can be swung to position over the die wherever it is placed on the sheet material, and the arm is then caused to strike a heavy blow with firm pressure upon the die to force it to cut through the sheet material,

The pressure thus .placed on the die, with unevenness of the cutting platform, inequalities of the thickness and strength of the sheet material, and the rigidity of the die, results in the breaking of a great many of these dies and their life i generally short. In addition, these dies used to cut out shoe Vamps are frequently provided with a re-entrant portion corresponding to the instep of the shoe, and it is necessary or desirable to support and reinforce the re-entrant portion to the sides of the die so that it will hold its position and shape at all times and not become distorted. Efforts to provide sufficient strength for the die and at the same time flexibility to prevent its breaking, and thus correct the defects of previous dies, have thus far not solved the problem. Previous dies of this type, of which I am aware, have been braced by reinforcing straps welded between the sides of the die, or the sides of the die and the reentrant portion, and which straps lie vertically and parallel with the sides of the die. Such reinforcing straps have proved unsatisfactory, have failed to solve the problem of proper balance between rigidity and flexibility of the die, and have introduced other problems of their own-such as, forcing the die out of shape during the tempering and hardening operations and requiring additional and difiicult straightening procedures.

I believe I have solved these problems and have overcome the defects and disadvantages of previous die constructions by my present constructionwhich consists briefly in means for flexibly reinforcing the die, including lips or brackets fixed to the inner sides of the die to which the ends of a strap connecting the two lips or brackets is fixed in any suitable manner. Other objects and advantages will appear from the accompanying specification and drawings in which:

Fig. 1 is a plan view of a die embodying my invention;

Fig. 2 is a vertical section on line 22 of Fig. 1; and

Fig. 3 is a vertical section through a modified structure.

In the drawings l0 represents a continuous, flat, metal strip, preferably of steel, shaped to correspond to the outline or contour of the piece desired to be cut out-in this instance, a shoe vamp. The die lies fiat with its sides vertical, with either or both top and bottom edges H and I2 sharpened to provide a continuous cutting edge. The die is formed by taking a flat strip of metal die stock, forming it into the desired shape on a bending machine, and welding the ends together as at point I3. The size marks or nicks It are then placed on the top and bottom edges ll and E2. Brackets or lips l5 are then welded to the inner side portions of the die, as shown in the drawings. The bracket or lip I5 is preferably U-shaped, with upper and lower arms Ma and I52). But it is to be understood that bracket 15 can have a single arm if desired. In this form the die is then tempered and hardened in a gas oven by heating it to the proper temperature and quenching it. If the die becomes distorted or out of shape during these operations, it can readily be straightened and brought back to the desired shape and is then tested for any weakness. A fiat metal strap I8 is then inserted between the upper and lower arms l5a and i519 of each bracket IE or adjacent the single arm (if only a single arm is provided), fixed to the brackets l5 in any suitable manner, as by welding or riveting, thus connecting each bracket and the two inner sides of the die and reinforcing it. Before or after being fixed to the brackets 15, the strap I8 is stamped with the size number and other desired information, such as the shoe last number.

A die reinforcing member of this nature has many advantages. When a one-piece vertical brace is welded between the sides of the die, as in the old practice, it throws the die out of shape and it has to be straightened and the brace lengthened or shortened. When the die is hardened and tempered after the usual vertical brace has been inserted, the difficulty of straightening 3 the die is greatly increased and many dies are broken or cannot be straightened to proper shape. These difficulties are all avoided by my construction.

By making the brace or supporting member in separate parts, with the attaching brackets i5 first welded to the sides of the. die and the connecting strap 18 then fixed, in turn, to the brackets, a strap 58 of the precise required length can be used, with no necessity of subsequent lengthening or shortening of the brace. The connecting strap 8 is preferably riveted to the brackets 15 by a central rivet 20, but it is to be understood that the pieces can be welded, bolted or otherwise attached if desired.

Attaching the reinforcing member in a horizontal plane transverse to the sides of the die has the important advantage of permitting greater flexibility, with great reduction in breakage of the die during use. Because of its flexibility, the die will cut through many thicknesses of sheet material with one stroke or blow of the clicker arm. The horizontal plane of the reinforcing member also permits the die to pick up many more thick nesses of the blank material with each out which greatly facilitates handling the blanks. Another incidental advantage of the horizontal mounting of the reinforcing strip is that it permits the die size to appear on the die in a position where it can be readily seen, the dies being usually hung on pegs in the shoe factory.

In Fig. 3 I have shown a modification of my device, wherein the stab or pin 25 is mounted in the bracket portion l5, thereby eliminating a separate bracket for this purpose. The purpose of stab or pin 25 is to place a mark (pin hole) upon the vamp, for instance, to indicate the place at which another piece of material is to be stitched to the vamp,

I claim:

1. A cutting die for cutting out blank from sheet material, comprising a continuous, flat, metal strip shaped to correspond to the outline of the blank to be cut out, the strip having upright sides with its edges lying in spaced parallel planes and at least one of said edges being a continuous cutting edge, and means for flexibly reinforcing said die, including brackets fixed to the inner sides of said die and a strap fixed horizontally to said brackets connecting said sides.

2. A cutting die for cutting out blanks from sheet material, comprising a continuous, flat, metal strip shaped to correspond to the outline of the blank to be cut out, the strip having upright sides with its edges lying in spaced parallel planes and at least one of said edges being a continuous cutting edge, and means for flexibly reinforcing said die including U-shape'd brackets fixed to opposite inner sides of said die and a strap fixed horizontally to said brackets connecting said sides.

3. A cutting die for cutting out blanks from sheet material, comprising a continuous, flat, metal strip shaped to correspond to the outline of the blank to be cut out, the strip having upright sides with its edges lying in spaced parallel planes and at least one of said edges being a continuous cutting edge, and means for flexibly reinforcing said die including U-shaped brackets horizontally fixed to opposite inner sides of said die and a strap lying in a horizontal plane and fixed between the arms of said brackets connecting said sides.

HARRY M. BOLSTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,334,379 Bolston M Nov. 16, 1943 1,990,154 Wright et a1 Feb. 5, 1935 1,340,235 Lund May 18, 1920 2,298,041 'Dedrick Oct. 6, 1942 

